Field
This document relates to a touch screen device and a method for driving the same.
Related Art
A user interface (UI) enables the communication of a user with various kinds of electric and electronic devices, so that the user can easily control the devices. Representative examples of the user interface are a keypad, a keyboard, a mouse, an on-screen display (OSD), a remote controller having an infrared communication or radio frequency (RF) communication function, and the like. The user interface technology has continuously developed to improve the user's sensitivity and ease of operation. The user interface has evolved into a touch UI, a voice recognition UI, a 3D UI, etc. The touch UI tends to be adopted in portable information devices, but has also expanded to electronic home appliances.
As one example of a touch screen for implementing the touch UI, a mutual capacitance type touch screen device that can respectively recognize multiple touches is gaining popularity.
The mutual capacitance type touch screen device includes a touch screen panel having Tx lines, Rx lines crossing the Tx lines, and touch sensors formed at crossings of the Tx lines and the Rx lines. Each of the touch sensors has mutual capacitance. The touch screen device senses a charge variation of each of the touch sensors between the time before and after a touch to determine the touch or non-touch with a conductive material and the position of touch. The touch screen device calculates touch coordinates by supplying a driving pulse to the Tx lines of the touch screen panel, converting charge variations of the touch sensors, which are received through the Rx lines, into touch raw data which are digital data, and analyzing the touch raw data.
The touch screen device can minimize an erroneous calculation by removing noise of the charge variations of the touch sensors. However, the range of the noise of the charge variations of the touch sensors may be slightly different according to different products. Due to this, a different noise filter for removing the noise of the charge variations of the touch sensors needs to be used depending on specific products.